Despite important progress toward identifying behavioral health risk factors for different forms of cancer there are still considerable gaps in understanding what leads certain individuals to engage in health promotion behavior, and why some individuals all-too-often continue to put their health at risk. Significance insight may be gained by considering the deeper motivational and psychological processes that are elicited when people are confronted with, both consciously and unconsciously, thoughts of cancer and, ultimately, their death. Indeed, an increasing amount of social psychological research indicates a diverse array of self-regulatory processes (both cognitive and behavioral) function to protect individuals from concerns associated with mortality. Yet there have been few applications of these ideas or research to behavioral health. The present application addresses this gap by integrating ideas about psychological consequences of fears of death with behavioral risk factors for cancer. The hypotheses guiding this research are that concerns about death and cancer can engender two types of psychological defense, each of which may have adaptive or maladaptive health implications. In response to conscious fears about cancer and death, "direct" psychological defenses aim to reduce perceived vulnerability. In response to unconscious death-related fears, "symbolic" psychological defenses are directed toward maintaining a sense of meaning and self-esteem: such efforts may occur along health-relevant dimensions (e.g., tanning to improve one's appearance). Fifteen experimental studies are proposed to explicate the conditions associated with each type of defense, and when, how, why, and for whom thee defensive strategies have adaptive (e.g., intentions to conduct self-breast exams) or maladaptive (e.g., avoidance of health information) implications for risky (e.g., smoking) and preventative (e.g., using sun screen) behaviors. This research program thus has the potential to illuminate previously unrecognized factors in cancer risk prevention. By highlighting the importance of peoples' motivation to remove thoughts of death from consciousness and to defend against unconscious mortality concerns, education and interventions fostering cancer prevention can be markedly improved.